Once you find the right scent, you stay loyal to it—or at least most men do. But what happens when your old standby starts to smell a little…off? Here are some of the possible causes for your cologne not smelling its best and how to fix them.

A quite nice video short from TED about how to train your nose and benefit from it. Some perfumers can distinguish individual odours in a fragrance made of hundreds of scents; tea experts have been known to sniff out the exact location of a particular tea.